Giant Cell Arteritis (GCA), also known as temporal arteritis, is a condition where the blood vessels, particularly the temporal arteries (located on the sides of the head), become inflamed, thickened, and narrowed. This condition primarily affects older adults and can lead to severe complications if not treated promptly, including vision loss or stroke.
Key Features of Giant Cell Arteritis:
- Cause and Pathogenesis:
- The exact cause of GCA is unknown, but it is thought to be an autoimmune disorder in which the body's immune system mistakenly attacks the blood vessels, particularly the medium and large arteries.
- GCA is often associated with another inflammatory condition called polymyalgia rheumatica (PMR), which causes muscle pain and stiffness.
- Symptoms:
- Headache: One of the most common symptoms is a severe headache, often located over the temples, hence the name "temporal arteritis."
- Scalp tenderness: The scalp may become tender, especially when combing or touching the hair.
- Jaw claudication: Pain or tenderness in the jaw when chewing, which occurs due to reduced blood flow to the muscles that control jaw movement.
- Vision problems: Blurred vision, double vision, or even sudden vision loss in one eye. Vision loss is a major concern in GCA and can be irreversible if not treated promptly.
- Fatigue: Individuals may feel unusually tired or fatigued.
- Fever: Low-grade fever may be present, often accompanied by night sweats and unexplained weight loss.
- Pain or stiffness in the shoulders, hips, and neck: This is a symptom of polymyalgia rheumatica (PMR), which often accompanies GCA.
- Diagnosis:
- Blood tests: Elevated levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), which are markers of inflammation, are commonly found in people with GCA.
- Temporal artery biopsy: The gold standard for diagnosing GCA. A small sample of the temporal artery is taken and examined under a microscope for signs of inflammation and giant cells.
- Ultrasound of the temporal arteries: A non-invasive imaging technique used to detect inflammation in the arteries.
- Magnetic resonance angiography (MRA) or computed tomography angiography (CTA): These imaging techniques may be used to detect blood vessel involvement in the head and neck.
- Treatment:
- Corticosteroids (steroids): The mainstay of treatment for GCA is high-dose oral corticosteroids (such as prednisone) to reduce inflammation. Steroids need to be started quickly to prevent complications like vision loss. The dose may be reduced gradually over time as symptoms improve.
- Aspirin: Low-dose aspirin may be recommended to reduce the risk of blood clots and complications, especially those related to the eyes or brain.
- Other immunosuppressive drugs: In some cases, drugs like methotrexate or tocilizumab (an IL-6 inhibitor) may be used to help manage inflammation if steroids alone are not sufficient.
- Monitoring: Patients are carefully monitored for side effects of steroid treatment, such as osteoporosis, diabetes, or gastrointestinal issues.
- Complications:
- Vision loss: If untreated, GCA can cause sudden and permanent blindness in one or both eyes due to reduced blood flow to the optic nerve.
- Stroke: GCA can also increase the risk of stroke due to reduced blood flow in the arteries.
- Aortic aneurysm: In rare cases, GCA can lead to inflammation in the aorta, increasing the risk of an aneurysm (a bulge in the artery wall that may rupture).
- Prognosis:
- With prompt treatment, the prognosis for GCA is generally good. Vision loss and other serious complications can often be prevented with early diagnosis and treatment.
- Relapse: Some patients may experience a recurrence of symptoms after reducing or stopping steroids, so they require long-term monitoring.
- Steroid side effects: Long-term use of steroids can cause side effects, so doctors will aim to minimize the dose as much as possible while managing the disease.
- Risk Factors:
- Age: GCA primarily affects individuals over the age of 50, with the risk increasing with age.
- Gender: Women are more commonly affected than men.
- Genetic factors: There may be a genetic predisposition to developing GCA, although the specific genes involved are not well understood.
- Other autoimmune diseases: Individuals with a history of other autoimmune conditions, such as rheumatoid arthritis, may be at higher risk.
